Large turbine dynamoelectric machines, such as generators, typically include internal cooling systems formed from a plurality of ducts in stator and rotor slots. Most generator cooling systems divide the internal spaces into a network of cooling pathways using a plurality of annular baffles. More specifically, the baffles divide the air gaps found between the stator and rotor assemblies and create a plurality of cooling zones in the cooling system. Cooling gases may be sent through these cooling zones using a blower to create high pressure zones in some of the cooling zones. For instance, alternating zones are connected to the high pressure side of a blower mounted on a rotor shaft, and the remaining zones are coupled to the low pressure side of the blower. Radial ducts through the rotor in each zone permit cooling gases to flow from the high pressure zones to the low pressure zones. Thus, the blower may move cooling gases through the cooling system.
At least one factor affecting the efficiency of dynamoelectric cooling systems is the amount of leakage past the air gap baffles. Baffle systems provide seals between rotors, which rotate relative to stators, and stators. Thus, baffles cannot be fixedly coupled to both rotors and stators. Rather, generators typically contain a plurality of baffles coupled to a rotor assembly and a plurality of baffles coupled to a stator assembly, which extend toward the baffles coupled to the rotor. Baffle systems are capable of being installed with minimal clearance between the stator baffles and rotor baffles. The rotor baffles may be formed from rings of non-magnetic material secured to the rotor surface at appropriate places along the rotor. The stator baffles may be aligned radially with the rotor baffles and are typically removably coupled to the stator to permit installation or removal of the rotor using conventional processes.
There exist numerous methods for attaching the stator baffles to a stator assembly. In at least one conventional approach, stator baffles are held in place with tapered wedges. The tapered wedges are in turn held in place with two guide cables formed of glass rope and a stainless steel tensioning cable which is tightened to lock the baffle segments in place. While this system enables baffles to be locked into position, the locking system is unnecessarily complex. Thus, a need exists for a more simplistic, efficient system for removable coupling air gap barriers to stator assemblies in dynamoelectric machines.